The MKK2 pathway mediates cold and salt stress signaling in Arabidopsis
The MKK2 pathway mediates cold and salt stress signaling in Arabidopsis
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DOI：
10.1016/j.molcel.2004.06.023
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发表时间：
2004-07-02
期刊：
影响因子：
16
通讯作者：
Hirt, H
中科院分区：
文献类型：
--
作者：
Teige, M;Scheikl, E;Hirt, H
利用拟南芥细胞分裂原活化蛋白激酶（MAPK）激酶2（MKK 2）及其下游蛋白激酶MPK 4和MPK 6的功能互补突变体，分离得到拟南芥MAPK激酶2（MKK 2）。在拟南芥原生质体中，MKK2被冷和盐胁迫以及胁迫诱导的MAPK激酶激酶MEKK1特异性激活。酵母双杂交、体外和体内蛋白激酶测定显示，MKK 2直接靶向MPK 4和MPK 6。因此，过表达MKK2的植物表现出组成型MPK4和MPK6活性，组成型上调胁迫诱导的标记基因的表达，并增加抗冻性和耐盐性。相反，mkk2无效植物MPK4和MPK6活化受损，对盐和冷胁迫非常敏感。对MKK 2过表达植物的全基因组转录组分析表明，参与转录调控、信号转导、细胞防御和胁迫代谢的152个基因的表达发生了改变。这些数据确定了一个MAP激酶信号级联介导的植物耐冷和耐盐胁迫。
The Arabidopsis mitogen-activated protein kinase (MAPK) kinase 2 (MKK2) and the downstream MAPKs MPK4 and MPK6 were isolated by functional complementation of osmosensitive yeast mutants. In Arabidopsis protoplasts, MKK2 was specifically activated by cold and salt stress and by the stress-induced MAPK kinase kinase MEKK1. Yeast two-hybrid, in vitro, and in vivo protein kinase assays revealed that MKK2 directly targets MPK4 and MPK6. Accordingly, plants overexpressing MKK2 exhibited constitutive MPK4 and MPK6 activity, constitutively upregulated expression of stress-induced marker genes, and increased freezing and salt tolerance. In contrast, mkk2 null plants were impaired in MPK4 and MPK6 activation and were hypersensitive to salt and cold stress. Full genome transcriptome analysis of MKK2-overexpressing plants demonstrated altered expression of 152 genes involved in transcriptional regulation, signal transduction, cellular defense, and stress metabolism. These data identify a MAP kinase signaling cascade mediating cold and salt stress tolerance in plants.